In early 13th Century Delhi became the capital of newly established Delhi Sultanate. A large number of military men suddenly made Delhi their home with large number of animals, slaves and some even with families. To cater to the traders, scribes and various men and women of service sectors and few other sectors, lots of water was required but the topography of Delhi despite a perennial river was water deficient. In mehrauli area there are historical wells that had not yielded water. The distance from river and being the end of rocky Aravali were the two factors that troubled the Delhi Sultanate. Water table was naturally very low. To add to the problem, the new rulers were poor in hydraulic engineering, having very poor idea of water management. They were fighting army with mobile population and very little idea of water storage and continuous usage.